Going Water to Air

[scratchgolf135]

I've seen this done but don't see much conversation on it here. I'm getting ready to build this out but thought I'd ask if anyone on here has moved to it and if so, what are your thoughts on improvement or any issues you've seen?

I'm bottom mount single so it's going to make for a clean install and will tidy up plumbing on the hot side substantially. I'll be going with the Wagner s55 intercooler (need to list my 7.5" HD VRSF on here, it's like new). I spoke to Davies Craig and they recommended a brushless magnetic pump (EBP40) running straight off ignition full tilt, no speed variation.

[iminhell1]

I'll go with the why question.


For any track racing, adding another fluid to the car is just adding more points of failure, fluid under a tire and potential crashes. I see zero benefits from a safety standpoint.

I know lots of drag guys who run a A2W and ice (or dry ice). It's almost always because they are class limited, working the piss out of the turbos (well out of efficiency range). It's the last case slight advantage they have for that extra power (that they can't put down anyways LOL).

IIRC you do mostly auto-x stuff. So basically 1 minute blasts at an average 50mph. If that's the case, I would say improved ducting to the A2A would be beneficial for you. Duct the back side to under the car, not to the engine bay. Make sure air has to go through the front, seals all around, force it through.

Any road racing you'll have the advantage of speed (more CFM through the core) to cool the core.

[scratchgolf135]

Because I like to try stuff and to solve problems that don't exist lol. Cooling benefit is actually bottom of the list although I do believe it will provide slightly improved IATs due to the thermal efficiency of water vs air. My case is more specific to my circumstance. I'm bottom mount single so improved plumbing all around. I've been working with Trackspec on e82 specific vents and they're finally ready. With that, it's going to put one of the side vents directly above my intake creating possible turbulence to my intake as the vent pulls air out. Eliminating the IC plumbing would allow me to move the air filter down into this area to prevent the above issue. Again, likely problem that's possibly not a problem but why not try W2A. For me, trying stuff/working on my car is every bit as fun as driving it.

[scratchgolf135]

There’s also the significant difference in boost loss and spool speed. Of the benefits of W2A, IAT is probably the lowest on the list. Albeit still an improvement over A2A.

[e80two]

Are you a member over on $p00lstreet?

https://www.$p00lstreet.com/threads/s55-intercooler-setup-on-an-e90-n55.8663/

You'll have to sub out the $ and the zeros, of course. This link is censored.

[scratchgolf135]

Originally Posted by e80two

Are you a member over on $p00lstreet?

https://www.$p00lstreet.com/threads/s55-intercooler-setup-on-an-e90-n55.8663/

You'll have to sub out the $ and the zeros, of course. This link is censored.

I am and have reviewed that thread thoroughly.

[e80two]

I'm leaning on the retrofit myself, but primarily b/c I want to run an Interchiller. The summers here are brutal, and I'd like to have every advantage I can get.

[scratchgolf135]

Originally Posted by e80two

I'm leaning on the retrofit myself, but primarily b/c I want to run an Interchiller. The summers here are brutal, and I'd like to have every advantage I can get.

Yea those interchillers are pretty awesome. Don't think I'll go that far but the benefits for me seem obvious. Faster spool with less pressure loss, less weight on the nose of the car, and being bottom mount single, the plumbing will be much cleaner. If I want 25psi and only have to command 25.5psi from the turbo rather than 28psi I'm creating less heat from the get go and getting to peak boost faster.

[wheela]

Originally Posted by scratchgolf135

Yea those interchillers are pretty awesome. Don't think I'll go that far but the benefits for me seem obvious. Faster spool with less pressure loss, less weight on the nose of the car, and being bottom mount single, the plumbing will be much cleaner. If I want 25psi and only have to command 25.5psi from the turbo rather than 28psi I'm creating less heat from the get go and getting to peak boost faster.

Excited to see how this turns out. I haven't seen any comparisons of pressure drop across air-to-water and air-to-air intercoolers, are the air-to-waters that much less restrictive? Or is it more the shorter plumbing required? Obviously there's less volume to pressurize, but that's extra nice if pressure drop is significantly less between the turbo outlet and throttlebody. The guy in that other post said it seemed more responsive, so that's promising.

Also, what turbo are you running?

[scratchgolf135]

Yep, much less volume to pressurize. From what I’m seeing most of our larger stepped ICs have a pressure drop around 3 psi vs .25-.5 for W2A.
I’m running a 6466 gen 2 bb.

[wheela]

Originally Posted by scratchgolf135

Yep, much less volume to pressurize. From what I’m seeing most of our larger stepped ICs have a pressure drop around 3 psi vs .25-.5 for W2A.
I’m running a 6466 gen 2 bb.

Nice, did you go with a kit or fab something up custom?

[scratchgolf135]

Originally Posted by wheela

Nice, did you go with a kit or fab something up custom?

Speedtech bottom mount.

[wheela]

Originally Posted by scratchgolf135

Speedtech bottom mount.

Nice choice

[ShocknAwe]

I'll likely do W2A at some point if I keepy N54, honestly leaning pretty heavily to a V8 swap. W2A for the people who have accomplished it was not cheap.

[scratchgolf135]

Really depends on if you want it to have a variable speed water pump. I supposed the fab cost for outlets on twins could add up but for bottom mount single, the plumbing is simple and minimal since my compressor outlet already points up. The only substantial cost is the actual cooler. The pump and heat exchanger will only total about $500. That and mine isn’t a daily so minimal miles driven so I’ll be running the water pump full tilt. I spoke to Davies Craig and they actually recommended this over any kind of PWM control.